0:01

And juxtapose that with, uh, our next case,

0:06

an adult similar findings.

0:09

Okay? And, uh, this patient, obviously, I don't apologize,

0:13

I I don't have radiographs on this case available,

0:16

but a similar case,

0:18

but, uh, this obviously involving the left hip

0:21

and let's h hang our images similar to the previous case,

0:27

and we'll just sort of do hors on top axials

0:31

and a sagal on bottom.

0:32

But, uh, we have the luxury of, uh, a post

0:37

contrast here, here,

0:43

uh, let's do this one right here.

0:45

Alright. So, again, we see sort of, uh, similar

0:48

to the previous case, I'll toggle sort

0:50

of back and forth, right?

0:52

Um, this, um, here, this is more ossified rec,

0:55

calcified bodies here.

0:57

Uh, we can, we can appreciate that this is more, uh,

1:01

T two bright, so, uh, sort of a related pathology, okay?

1:06

And, but this more immature, I guess if you want,

1:09

if you can call it that, this way.

1:10

But obviously this case has more fluid, um, fluid components

1:15

or cila components, as, as you can see, as we can see here,

1:18

rather than ossific

1:20

or, uh, um, calcific components, uh, leading to that, uh,

1:24

ossification or calcification of this conroy matrix.

1:28

But this actually was a scary case for me

1:30

and, uh, uh, learned quite a bit from this.

1:33

And I just wanted to share a few things.

1:34

But this turned out to be a, a pathology proven case of

1:39

synovial, uh, chondro sarcoma, okay?

1:41

Rather than a, uh, synovial ocon mitosis

1:45

or con mitosis, okay?

1:47

Uh, sort of a, a spectrum, okay?

1:50

But, uh, a few things

1:51

that I've learned from this case about synovial

1:53

chondro sarcoma, okay?

1:55

Very rare entity can scare the bejesus out of us.

1:58

And typically, or depending on who you read, uh,

2:01

last I checked over the weekend,

2:03

there are about 40 cases described in the literature, okay?

2:07

40 or so. Okay?

2:09

And about five of those four

2:11

or five of those, if I remember correctly, there,

2:12

they were de novo.

2:14

The most common location

2:15

of synovial conjun sarcoma is the knee followed

2:19

by typically the hip, as in our case here, okay?

2:23

And it can be very, very, very difficult to parse out, okay?

2:29

Whether this is a synovial con mitosis

2:32

or synovial Congo sarcoma as in this case

2:35

that we have up here, okay?

2:37

Some things that have been written out in written

2:39

or discussed in the literature

2:40

that could in theory help, right?

2:42

Are going to be pain

2:44

or new pain, uh, clinical deterioration, okay?

2:47

On the clinical side, radiologically or by MR.

2:50

Imaging, as we see here, it can be very, very difficult.

2:54

Okay? Some things that could help us are invasion, okay?

2:58

And bony involvement.

2:59

But as in this case, jumping back

3:01

to the previous synovial con mitosis

3:03

or osteochondrosis osteo mitosis case,

3:06

we see this chronic involvement

3:08

and remodeling of bone in, uh, in about

3:13

anywhere from 50 to 80%, depending on who you read of, uh,

3:17

osteos involvement with synovial chondral

3:19

or osteochondrosis.

3:20

So that doesn't really help us, okay?

3:23

So sometimes we'd have to pick up that needle

3:25

and go to, uh, pathology,

3:28

but that being said, it can even be hard

3:30

for our pathologist, okay?

3:32

But some tip-offs and things to think about, okay?

3:35

And we will get to diffusion weighted imaging or DWI, uh,

3:38

but, uh, the, some tipoff to help us

3:40

for our path pathology colleagues, okay?

3:44

Sometimes are going to be a few things, okay?

3:47

Um, it's what's said in the pathology literature.

3:50

If you look at the cell block, this, um,

3:53

synovial chondral sarcoma typically presents

3:56

as sheets of cells, okay?

3:58

Sort of infiltrative sheets of cells versus

4:01

synovial con mitosis is going to be more nodular

4:05

if you have mixed soy change, okay?

4:08

On your, on your radiologic studies

4:10

or your pathology, that bumps it up more suspicious

4:14

for condu sarcoma, obviously,

4:16

hyper cellularity at atypical nuclei, parti, partic,

4:21

particularly at the periphery, okay?

4:23

But the other thing, the, that you want to help, uh, help

4:26

to look out for is necrosis, okay?

4:28

And necrosis on our radiologic, uh, oh, timed out.

4:33

I apologize. Let's just pull that back up.

4:42

But if you see necrosis, okay? Mixed soy change, okay?

4:47

And that sheets and infiltrative nature, okay?

4:50

Whether on your radiology, radio radiologic images,

4:54

or in our pathology slides,

4:57

that's gonna tip us more towards worrying about

4:59

conjure sarcoma.

5:00

And it's actually been discussed a, um,

5:03

this infiltrative nature of these sheetlike nature

5:06

with the bony involvement.

5:08

And on, uh, our pathology slides, our pathologists,

5:11

you may hear, um, some, uh, trigger words such

5:14

as filling up, uh, along with the infiltration

5:18

of the aspace versus synovial con mitosis.

5:21

It's going to be, tend to be more nodular

5:24

and, uh, uh, less sheet like,

5:26

and less infiltrative is, uh,

5:28

what I learned from my pathology colleagues.

5:30

So what we can see here from this con, uh, case, a rare case

5:34

of synovial conjun sarcoma, we see that robust, uh,

5:38

involvement of the hip,

5:39

but also extending into the medial wall of the ace.

5:43

Tamil, obviously eating away at the quadrilateral, uh,

5:46

eating its way towards the quadrilateral plate,

5:49

and hopefully not, uh, violating the, uh, medial wall

5:52

of the ace tablum here.

5:53

But some important things to re uh, uh, highlight

5:57

With, uh, your tumor, uh, reads if you're doing, uh,

6:01

tumor uh, imaging.

6:03

So now, uh, just wanna throw up the, uh, uh,

6:07

diffusion weighted imaging.

6:09

Uh, and, uh, just to highlight, okay, uh,

6:12

there was a couple questions about diffusion

6:14

weighted imaging.

6:15

And briefly, um, in my humble opinion, um,

6:19

diffusion weighted imaging is just not there

6:22

yet the way it is with, uh, neuroradiology.

6:25

Um, let's say, especially with, obviously ischemic imaging,

6:29

you gotta really know, depending on the histology, uh,

6:34

and even grade of what you're dealing with in MSK, uh,

6:38

tumor imaging, um,

6:40

diffusion wage weighted imaging does not really help.

6:43

Okay? For instance, in this case, it's not gonna help

6:47

with our cartilaginous tumors, right?

6:49

So it's, you're basically need to see water,

6:52

and if you throw up an a DC on this,

6:54

it's also gonna be bright.

6:55

So, but you're still not going to not chase this

6:59

and not biopsy this for the fear of that rare chora sarcoma.

7:02

And again, remember that chora sarcomas of the pelvis, one

7:06

of the most common, uh,

7:07

malignancies in adult pelvises, right?

7:10

Other things where diffusion weight

7:12

and imaging really doesn't help us out, okay?

7:15

In MSK imaging lan, right?

7:17

Besides, uh, chondro sarcomas, uh, it's a correlate

7:21

of other conroy lesions as we talked previously with, uh,

7:24

synovial con mitosis, right?

7:26

Uh, and then take the other, um, uh, it can,

7:31

it can help sometimes with abscesses,

7:34

but typically, in my opinion,

7:35

and what I've noticed, uh, in, in, in my hands with, uh,

7:38

diffusion weighted imaging, uh, it, you're gonna get

7:41

that history of concern for infection.

7:43

You're gonna have the, uh,

7:44

overlying ulcers you to tip you off.

7:47

And then, uh, it looks like an abscess by imaging, right?

7:51

On our qualitative imaging

7:53

that is our anatomic weighted imaging.

7:55

So, diffusion weighted imaging really, uh, in my opinion,

7:57

helps us more, uh, incrementally as a quantitative, uh,

8:02

uh, imaging adjunct, uh, in MR imaging of tumors in, uh,

8:07

musculoskeletal, uh, land.

8:09

Okay? Take the opposite.

8:10

When you're dealing with diffusion rate, I, I, I, I, um,

8:14

raise caution, right?

8:16

Um, if you're dealing with a hemorrhagic lesion, let's,

8:20

let's take the example of, uh, PVNS

8:22

or the artist formerly known as PV NS, now known

8:25

as tial Giant Cell Tumor Intraarticular, diffuse type.

8:29

I know some of the panelists, uh,

8:31

today don't believe in that.

8:33

Um, they like the old terms, which is fine.

8:36

Whatever terms you use, just make sure we're communicating

8:38

effectively with our, with your, uh, referring clinicians.

8:41

But when something's really hemorrhagic, in the case of,

8:44

we'll call it PVNS, right?

8:47

Um, that will lead

8:49

to dark signal on your diffusion weighted imaging

8:51

and dark signal on your a DC.

8:54

Are you gonna stop there? No. Right?

8:56

So you're still going to get,

8:57

and in that case, you're gonna get what's called, um,

9:00

T two Black through, right?

9:02

If you read, if you're reading literature

9:03

and studying diffusion, diffusion weight

9:05

and imaging, other lesions that can have T two black

9:08

through okay, are on your ADCs are your

9:11

fibrous lesions, right?

9:12

Maybe perhaps like a desmoid, um, what have you,

9:16

or a fibro sarcoma

9:18

and that sort of spectrum, so that, uh,

9:21

potentially can happen too.

9:22

So, diffusion weighted imaging,

9:24

although can be helpful in certain instances, right?

9:27

Uh, osteomyelitis, uh, some tumors

9:30

and abscesses, in which case your a DC, that value

9:33

that you're gonna be looking for, that cutoff, typically,

9:35

depending on who you read, is gonna be about one, uh,

9:39

millimeter squared per second.

9:41

Okay? That's the, the cutoff range.

9:44

Um, and depending on how you're obtaining your B values

9:47

and what have you, uh,

9:48

and we could talk about more that, uh,

9:49

with some questions and answers.

9:52

But, uh, in general, in my opinion, to summarize,

9:55

diffusion weighted imaging, uh, can help.

9:58

But, uh, you shouldn't be using it solely as your, as your,

10:01

uh, sole, um, imaging, uh, diagnosis for various bone tumors

10:06

or soft tissue tumors.